This proposal is for a 2-year study to build an interdisciplinary network for research on the role of culture on risk perception and behavior - in particular the relationships among perceptions of health risks, social networks, and culture. Individuals perceive health risks through cognitive and emotional processes, but individual differences in risk perception are influenced by social experiences and cultural frames of reference. For example, sub-populations have differing levels of medical knowledge about HIV risk, and some groups may espouse lay theories about the origin, nature, and risk of HIV. Furthermore, individuals can be heavily influenced by the experiences of others in their social network, such as a friend or family member contracting HIV. Currently, separate lines of research address the role of individual experiences, social networks, and cultural processes in determining how individuals perceive the risk of various health outcomes and how this in turn conditions engagement in risky behaviors. This project will bring together anthropologists, psychologists, economists, and mathematicians to build interdisciplinary theory and methods that synthesize the individual, social, and cultural elements of risk perception. We will build thi collaborative network in multiple phases. First, we will conduct team-building meetings to introduce our previous research and to identify overlapping or complementary theory, methods and research questions. Our proposed network of researchers has produced a large body of published papers and primary data concerning the role of individual differences and individual experiences, social networks, and cultural dynamics in the determination of risk perception and risk behaviors (both with respect to HIV and other outcomes). We will focus on how to incorporate culture into studies that currently lack an adequate measure of cultural process as well as how to incorporate non-cultural elements into studies of culture. Next, we will build a repository of data sets from our existing studies and re-analyze these data in order to: 1) build familiarity of theories, methods and research questions across disciplines, and 2) generate novel hypotheses for future research. Then, we will collaboratively design and conduct a small mixed-method pilot study of the HIV risk beliefs and practices of homeless people living in Skid Row. The pilot project will be informed by insights generated through cross-disciplinary team conversations and secondary data analyses as well as our team's previous research on HIV risk behaviors, risk perceptions, and social networks among homeless men, women, and youth in Los Angeles. Finally, findings from this study as well as methods and theory developed will be disseminated to the wider academic community, and the project team will develop full research proposals building on the insights and tools developed from their collaborative work.